This disclosure relates to an image forming apparatus, and in particular relates to an image forming apparatus that includes a plurality of units connected with each other in a vertical direction.
Conventionally, a small image forming apparatus such as a printer can print on sheets of paper of various sizes and on a large number of sheets of paper by selectively connecting units configured for a sheet feed function above or below a unit configured for an image forming function.
A setup is used for connecting the units described above. In this setup, one locating portion (for example, a recessed portion) disposed on a lower surface of an upper unit is engaged with another locating portion (for example, a projecting portion) disposed on an upper surface of a lower unit. A heavy-weight image forming apparatus may also include a connection mechanism operated by a user in addition to the locating portion described above. For example, a setup is known in which units are connected with each other by an automatically or manually moveable hook.
Although engagement of the locating portions as described above can restrict the upper unit from displacing horizontally relative to the lower unit, it is not possible to restrict the upper unit from displacing vertically relative to the lower unit. In this manner, there is a risk that the locating portions may disengage from each other due to an impact caused by such as an earthquake or a body colliding with the image forming apparatus and the upper unit may accordingly separate from the lower unit. When a connection mechanism configured to be operated by a user is provided, there is a possibility that the user may forget to operate the connection mechanism. Consequently, there is a risk of occurrence of a similar problem since the connection mechanism is not always be used properly by the user.
When the units are connected with each other by the moveable hook, a mechanism configured to operate this hook is required. Consequently, it will be difficult to mount the movable hook in a small image forming apparatus due to spatial restriction. Furthermore, there is a risk of an increase in costs due to an increase in the number of components. In particular, when a mechanism for sliding the unit is required in addition to the moveable hook, serious problems further arise in relation to space and cost.